Qualcomm QCA199x NFC NCI device

Near Field Communication (NFC) device is based on NFC Controller Interface (NCI)

Required properties:

- compatible: "qcom,nfc-nci"
- reg: NCI i2c slave address.
- qcom,dis-gpio: specific gpio for hardware reset.
- qcom,irq-gpio: specific gpio for read interrupt.
- qcom,clk-src: nfc clock source ("BBCLK2", "RFCLK3", "GPCLK", "GPCLK2", ...)
- qcom,clk-src-gpio: msm gpio clock,used ony if clock source is msm gpio
- qcom,clk-req-gpio: clk-req input gpio for MSM based clocks.
                     not used for pmic implementation
- interrupt-parent: Should be phandle for the interrupt controller
                    that services interrupts for this device.
- interrupts: Nfc read interrupt,gpio-clk-req interrupt
- qcom,clk-gpio: pmic or msm gpio on which bbclk2 signal is coming.

Example:

	i2c@f9925000 { /* BLSP-1 QUP-3 */
		nfc-nci@e {
			compatible = "qcom,nfc-nci";
			reg = <0x0e>;
			qcom,irq-gpio = <&msmgpio 77 0x00>;
			qcom,dis-gpio = <&msmgpio 93 0x00>;
			qcom,clk-src-gpio = <&msmgpio 78 0x00>;
			qcom,clk-src = "GPCLK2";
			interrupt-parent = <&msmgpio>;
			interrupts = <77 0>;
			qcom,clk-gpio = <&msmgpio 75 0x00>;
		};
	};

